Publications by authors named "Aram Rostami"

8 Publications

  • Page 1 of 1

Novel treatment setup for urethral carcinoma radiotherapy: A complete response case report.

Clin Case Rep 2020 Dec 7;8(12):2860-2864. Epub 2020 Sep 7.

Therapy Level Laboratory Secondary Standard Dosimetry Laboratory (SSDL) Karaj Iran.

A homemade personalized penis holder can provide the reproducibility of the penis during urethra carcinoma (UC) radiotherapy.
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http://dx.doi.org/10.1002/ccr3.3329DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7752605PMC
December 2020

Application of rectal retractor for postprostatectomy salvage radiotherapy of prostate cancer: A case report and literature review.

Clin Case Rep 2019 Nov 27;7(11):2102-2107. Epub 2019 Sep 27.

Department of Medical Physics School of Medicine Iran University of Medical Sciences Tehran Iran.

Using a rectal retractor (RR) during salvage radiotherapy after radical prostatectomy is a promising approach for reducing dose to the rectum. The patient well tolerated the daily RR insertion. This area of research encourages researchers for a comprehensive evaluation of the role of the RR in postprostatectomy radiotherapy.
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http://dx.doi.org/10.1002/ccr3.2430DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6878068PMC
November 2019

Use of artificial neural network for pretreatment verification of intensity modulation radiation therapy fields.

Br J Radiol 2019 Oct 24;92(1102):20190355. Epub 2019 Jul 24.

Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran.

Objective: The accuracy of dose delivery for intensity modulated radiotherapy (IMRT) treatments should be determined by an accurate quality assurance procedure. In this work, we used artificial neural networks (ANNs) as an application for the pre-treatment dose verification of IMRT fields based two-dimensional-fluence maps acquired by an electronic portal imaging device (EPID).

Methods: The ANN must be trained and validated before use for the pretreatment dose verification. Hence, 60 EPID fluence maps of the anteroposterior prostate and nasopharynx IMRT fields were used as an input for the ANN (feed forward type), and a dose map of those fluence maps that were acquired by two-dimensional Array Seven29 as an output for the ANN.

Results: After the training and validation of the neural network, the analysis of 20 IMRT anteroposterior fields showed excellent agreement between the ANN output and the dose map predicted by the treatment planning system. The average overall global and local γ field pass rate was greater than 90% for the prostate and nasopharynx fields, with the 2 mm/3% criteria.

Conclusion: The results indicated that the ANN can be used as a fast and powerful tool for pretreatment dose verification, based on an EPID fluence map.

Advances In Knowledge: In this study, ANN is proposed for EPID based dose validation of IMRT fields. The proposed method has good accuracy and high speed in response to problems. Neural network show to be low price and precise method for IMRT fields verification.
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http://dx.doi.org/10.1259/bjr.20190355DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6774604PMC
October 2019

Rectal retractor application during image-guided dose-escalated prostate radiotherapy.

Strahlenther Onkol 2019 Oct 1;195(10):923-933. Epub 2019 Mar 1.

Department of Biostatistics, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.

Purpose: To investigate efficacy of a rectal retractor (RR) on rectal dose during image-guided dose-escalated prostate three-dimensional conformal radiotherapy (3DCRT).

Patients And Methods: In all, 21 patients with localized prostate cancer were treated with a RR for 3DCRT in 40 × 2 Gy. Patient underwent two scans for radiotherapy planning, without and with RR. RR was used for the first half of the treatment sessions. Two plans were created for each patient to compare the effect of RR on rectal doses. PTW-31014 Pinpoint chamber embedded within RR was used for in vivo dosimetry in 6 of 21 patients. The patient tolerance and acute rectal toxicity were surveyed during radiotherapy using Common Terminology Criteria for Adverse Events (CTCAE) v.4.0.

Results: Patients tolerated the RR well during 20 fractions with mild degree of anal irritation. Using a RR significantly reduced the rectal wall (RW), anterior RW and posterior RW dose-volume parameters. The average RW D was 29.4 and 43.0 Gy for plans with and without RR, respectively. The mean discrepancy between the measured dose and planned dose was -3.8% (±4.9%). Grade 1 diarrhea, rectal urgency and proctitis occurred in 4, 2 and 3 cases, respectively. There were no grade ≥2 acute rectal toxicities during the treatment.

Conclusion: Rectal retraction resulted in a significant reduction of rectal doses with a safe toxicity profile, which may reduce rectal toxicity. Dosimeter inserted into the RR providing a practical method for in vivo dosimetric verification. Further prospective clinical studies will be necessary to demonstrate the clinical advantage of RR.
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http://dx.doi.org/10.1007/s00066-019-01445-6DOI Listing
October 2019

Cytogenetic damage from hyperthermia,6 MV X-rays, and topotecan in glioblastoma spheroids, simultaneously, and separately.

J Cancer Res Ther 2018 Oct-Dec;14(6):1273-1278

Department of Radiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Purpose: Glioblastoma multiform (GBM) is one of the most common brain tumors. Surgery, radiation therapy, hyperthermia, and chemotherapy are the most common treatments for brain tumors such as GBM. This study investigated the cytogenetic damage caused by hyperthermia, radiation (6 MV-X-rays), and topotecan in glioma spheroids, simultaneously and separately.

Materials And Methods: Human glioblastoma cell line was cultured to form spheroids 350 μm in diameter that were arranged in eight groups and coded as follows: control, T: topotecan, H: hyperthermia, T + H: topotecan + hypertermia, X 1-10: X-ray with 1-10 fraction irradiation, H + X (1-10): hypertermia + X-ray with 1-10 fraction irradiation, T + X (1-10): topotecan + X-ray with 1-10 fraction irradiation, and H + T + X (1-10): hypertermia + topotecan + X-ray with 1-10 fraction irradiation. DNA damage was then evaluated using clonogenic assay.

Results: The effect of combined treatment with X + H + T was greater than the sum of the effects in other groups. In H + T + X group, failure to form colonies was observed in the seventh session.

Conclusion: Use of X + H + T combination therapy significantly increased cell death and possibly improved the treatment. This suggests that the synergistic effect of different therapeutic methods increased cell death in glioblastoma tumor cells and reduced the necessary dose of radiation in the treatment of tumor in radiation therapy.
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http://dx.doi.org/10.4103/0973-1482.189239DOI Listing
February 2019

2D Dose Reconstruction by Artificial Neural Network for Pretreatment Verification of IMRT Fields.

J Med Imaging Radiat Sci 2018 Sep 4;49(3):286-292. Epub 2018 Jul 4.

Shohada-e-Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

The use of intensity-modulated radiation therapy (IMRT) is developing rapidly in clinical routines. Because of the high complexity and uniqueness of IMRT treatment plans, patient-specific pretreatment quality assurance is generally considered a necessary prerequisite for patient treatment. In this work, we proposed a modified methodology of electronic portal imaging device (EPID)-based dose validation for pretreatment verification of IMRT fields by applying artificial neural networks (ANNs). The ANN must be trained and validated before use for pretreatment dose verification. For this purpose, 20 EPID fluence maps of IMRT prostate anterior-posterior fields were used as an input for ANN (feed forward type) and a dose map of those fluence maps that were predicted by treatment planning system as an output for ANN. After the training and validation of the neural network, the analysis of 10 IMRT prostate anterior-posterior fields showed excellent agreement between ANN output and dose map predicted by the treatment planning system. The average overall fields pass rate was 96.0% ± 0.1% with 3 mm/3% criteria. The results indicated that the ANN can be used as a low-cost, fast, and powerful tool for pretreatment dose verification, based on an EPID fluence map.
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http://dx.doi.org/10.1016/j.jmir.2018.05.004DOI Listing
September 2018

Radioprotective effects of selenium and vitamin-E against 6MV X-rays in human blood lymphocytes by micronucleus assay.

Med J Islam Repub Iran 2016 10;30:367. Epub 2016 May 10.

PhD Student of Medical Physics, Department of Medical Physics, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.

Background: Critical macromolecules of cells such as DNA are in exposure to damage of free radicals that induced from the interaction of ionizing radiation with biological systems. Selenium and vitamin-E are natural compounds that have been shown to be a direct free radical scavenger. The aim of this study was to investigate the radioprotective effect of selenium and vitamin-E separately and synergistically against genotoxicity induced by 6MV x-rays irradiation in blood lymphocytes.

Methods: Fifteen volunteers were divided into three groups include A, B and C. These groups were given selenium (800IU), vitamin-E (100mg) and selenium (400IU) + vitamin-E (50mg), respectively. Peripheral blood samples were collected from each group before (0hr) and 1, 2 and 3hr after selenium and vitamin-E administration (separately and synergistically). Then the blood samples were irradiated to 200cGy of 6MV x-rays. After that lymphocyte samples were cultured with mitogenic stimulation to determine the chromosomal aberrations with micronucleus assay in cytokinesis-blocked binucleated cells.

Results: The lymphocytes in the blood samples collected at one hr after ingestion selenium and vitamin-E, exposed in vitro to x-rays exhibited a significant decrease in the incidence of micronuclei, compared with control group at 0hr. The maximum protection and decrease in frequency of micronuclei (50%) were observed at one hr after administration of selenium and vitamin-E synergistically.

Conclusion: The data suggest that ingestion of selenium and vitamin-E as a radioprotector substance before exposures may reduce genetic damage caused by x-rays irradiation.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4972055PMC
August 2016

Micronuclei Assessment of The Radioprotective Effects of Melatonin and Vitamin C in Human Lymphocytes.

Cell J 2016 4;18(1):46-51. Epub 2016 Apr 4.

Department of Radiotherapy, Hospital of Shohada Tajrish, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Objective: Critical macromolecules such as DNA maybe damaged by free radicals that are generated from the interaction of ionizing radiation with biological systems. Melatonin and vitamin C have been shown to be direct free radical scavengers. The aim of this study was to investigate the in vivo/in vitro radioprotective effects of melatonin and vitamin C separately and combined against genotoxicity induced by 6 MV x-ray irradiation in human cultured blood lymphocytes.

Materials And Methods: In this experimental study, fifteen volunteers were divided into three groups of melatonin, vitamin C and melatonin plus vitamin C treatment. Peripheral blood samples were collected from each group before, and 1, 2 and 3 hours after melatonin and vitamin C administration (separately and combined). The blood samples were then irradiated with 200 cGy of 6 MV x-ray. In order to characterize chromosomal aberrations, the lymphocyte samples were cultured with mitogenic stimulus on cytokinesisblocked binucleated cells.

Results: The samples collected 1hour after melatonin and vitamin C (separately and combined) ingestion exhibited a significant decrease in the incidence of micronuclei compared with their control group (P<0.05). The maximum synergic protection and reduction in frequency of micronuclei (57%) was observed 1 hour after vitamin C and melatonin administration combined.

Conclusion: We conclude that simultaneous administration of melatonin and vitamin C as radioprotector substances before irradiation may reduce genotoxicity caused by x-ray irradiation.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4819385PMC
http://dx.doi.org/10.22074/cellj.2016.3986DOI Listing
April 2016